The greatest challenge isn't the stifling heat but the crushing weight of those who failed before.

Irencrag Feat

Add seven {R}. You can cast only one more spell this turn.

Throne of Eldraine

Throne of Eldraine Promos

If an effect allows or instructs you to cast another spell after you cast one more, you can't do so. The restriction of Irencrag Feat takes precedence over that permission.

Irencrag Feat's effect doesn't allow you to cast any spell you couldn't otherwise cast. For example, if an effect says you can't cast more than one spell each turn, Irencrag Feat won't let you cast a second.

Irencrag Feat's effect doesn't care how many spells you've cast so far in the turn. You can cast only one more.

Irencrag Feat's effect doesn't stop you from activating any abilities or from playing lands.